Improvement in mallets for smoothing sheet metal



W. H. CLARK, A. 0. KITTREDGE '& W.Ul. CLARKl Mallets for SmoothingSheet-Metal.

n Patented Aug. 4, H574.

UNITED STATES PATENT OFFICE- WILLIAM H. CLARK, ANSON. O. KITTREDGE, ANDlWILLIAM J. CLARK,

` oFsALEM, oHIo.

IMPROVEMENT IN MALLETS FOR SMOOTHING SHEET METAL.

Specication forming part of Letters Patent N0. 153,663, dated August 4,1874; applisation filed May 4, 1874.

To all whom t may concern:

Be it known that we, WILLIAM H. CLARK, ANsoN 0. KIITREDGE, and WILLIAMJ. CLARK, of Salem, in the county of Columbia-na and State of Chio, haveinvented a certain new and Improved Mallet for Smoothing Sheet Metal 5kand we hereby declare that the following is a full, clear, and completedescription thereof, reference being had to the accompanying drawingsmaking part of the same.

Figure l is a side elevation of the machine. Fig. 2 is a plan View. Fig.3 is an end elevation. Fig. 4. is a detached section.

Like letters of reference refer to like parts in the several views.

The nature of this invention relates to a tilt hammer or mallet, and theobject thereof is to rapidly and eft'ectually smooth down the burr fromthe edges of sheet metaly caused by cutting the same with shears orother implements, and also to correct, by smoothing out, inequalities inthe surface of the sheet without subjecting the same to such force aswould tend to stretch the work and cause it to crinkle. Heretofore thishas been done by the strokes of a malletin the hands of a workman--aslow and necessarily tedious process, but which, by the use of thisinvention, is greatly expedited, and accomplished in a less wearisomemanner.

0f the construction and operation of the machine, the following is afull and complete description In the drawings, A represents a bed-plate,on which the tilt-hammer or malletis erected. The fore part B of theplate is raised above the face of the bed, and forms an anvil orstriking-surface for the mallet C. Said mallet consists of a shell orthimble, D, Fig. l, slightly tapering from the top downward. In theshell is iitted a wooden block, E, the lower end of which is allowed toproject below the shell, as shown in the drawing. The block E isintroduced into the shell from the top, and is secured therein by a cap,F, screwed into the shell. Interposed between the block and the end ofthe screw of the cap is a rubber cushion, a, Fig. 4, on which is imposedaplate of metal, b, to afford a bearing for the screw G, to compensatefor the wearing of the block.

H is the handle of the mallet. Said handle is a spring, consisting of abroad flat piece of steel, the end of which is fitted to and secured inthe end of the walking-beam I, whereof the pin J is its axial point lofvibration. The handle is guarded and strengthened by springs K, oneabove and one below the handle, and secured thereto, as shown in Fig. l.On the end of the shaft carrying the iiyvvheel and pulley L M (whichshaft has its bearing in the standard N and is indicated ,y by thedotted line a, Fig. 3) is a crank-wheel,

N, Fig. l, also indicated by the dotted line h, of which c, Fig. l, isthe crank-pin. Said pin is also indicated by the dotted line d. In theopen end of the vibrating beam I is fitted a sliding journal-box, O,Fig. 1, in which the crank-pin o revolves for operating the said beam.The box O referred to slides upon plates e, Fig. l, held inclose-fitting contact therewith by springs f, one above and one beloweach of the plates, as shown in Fig. 1.

Having described the construction and arrangement of the several partsof the machine, the practical operation of the same is substantially asfollows:

Motion is imparted thereto by a belt upon the pulley M, thereby causinga lively vibratory action of the beam I, and consequently that of themallet. The piece of sheet metal to be acted upon is laid upon the anvilB under the hammer or mallet, in the proper position to receive thestrokes thereof, which -is thereby quickly smoothed and straightened bytherapid and repeated blows given by the mallet. In consequence of thesprings f, in combination with the sliding box O, and the springs orguards K secured to the handle H of the mallet, together with the springor cushion a in the mallet, the rigidity of the blows is broken, and inlieu thereof is given an elasticity to the strokes, producing thenecessary percussion required to accomplish the work. Instead of themetallic springs j' rubber may be used, and in place of the rubbercushion in the mallet a metal spring may be used without in anywayeffecting the general result.

What we claim as our invention, and desire to secure by Letters Patent,is-

1. The combination of the mallet C, con-

